Electrolytic condenser



June 9, 1942. A M. GEORGIEV ETAL 2,286,081

` ELECTROLYTIC CONDENSER Filed July 19, 1939 93 INVENoRs alexander'earyrev B Paz/ i.' [foe/P61 Patented June 9, 1942 ELECTROLYTICCOND-ENSER Alexander M. Georgiev and Paul F. Koehly, Dayton, Ohio,assgnors to General Motors Corporation, Detroit, Mich., a corporation ofDelaware Application July 19, 1939, Serial No. 285,336

Claims.

This invention relates to electrolytic condensers and is moreparticularly concerned with those condensers having a thin mass ascompared with their relative length and breadth.

There is a considerably extensive field for the use of electrolyticcondensers of the flat type, that necessitates the use of shallowcontainers in order to provide an assembly that may be mounted in arelatively thin space, such as in the base of an electric motor and thelike. Another outlet contributing to the same demand is an instancewhere there is a need of several similar condenser units that are to becompactly installed in parallel, in series, or in series parallelrelation.

It is therefore an object of this invention to provide an electrolyticcondenser that while having prescribed electrical characteristics, willbe contained in a small volume and adaptable for alternative mountingand eflicient cooling.

It is also an object of the instant invention to provide container meansfor an electrolytic condenser that may be hermetically sealed withoutresort bein.U made to the handiwork of a skilled operator.

Another object of the invention is to provide a terminal structure foran electrolytic condenser having a metallic container, which terminalconstruction Will not only properly insulate the terminals from oneanother but will also effectively seal their support in the casingmember against iiow of electrolyte or vapors therefrom.

A further object is to secure a terminal member in a thin walled casing,so that it cannot be turned therein and result in shorting of theterminal connections and cause rupture of the electrode connectors.

A further object of the invention is to provide a container for anelectrolytic condenser that will obviate the necessity for a reliefvent.

A further object of the invention is to pro- Vide a condenserconstruction that will facilitate cooling of an enclosed structure.

The above objects are accomplished in main by providing twosubstantially symmetrical and cooperable casing members which arepreferably of drawn sheet metal, such as steel, sheet iron. tinned iron,or zinc, the drawings being shallow so as to be carried out in a singlestep. One of the housing members is provided with a pair of aperturesfor support of the electrode terminals, the material of the housingsurrounding the termina] apertures being depressed coincident with theoutside extension of the terminal members, thus reducing protuberantstructure to a minimum, and providing a structure capable of evenstacking without interference from terminals or protuberances on anadjacent structure. In mounting the terminals in the housing member,means are provided for insulating the terminals from the housing and atthe same time sealing the opening therethrough against the ilow ofelectrolyte or vapors therefrom.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawing wherein a preferred embodiment of the present invention isclearly shown.

In the drawing:

Fig. 1 is a plan view of a condenser constructed in accordance with ourinvention.

Fig. 2 is an end view of the same, substantially as indicated by thearrow 2 of Fig. 1.

Fig. 3 is a fragmentary view on an enlarged scale, with parts shown insection, substantially as indicated by the line and arrows 3-3 of Fig.l.

Fig. 4 is an exploded View, showing the relation of the elementscontributing to the terminal structure, the view being on an enlargedscale,

Fig. 5 is a view on a smaller scale, illustrating one method ofsupporting a plurality of condensers, incorporating the instantinvention.

With particular reference to the drawing, IB indicates an electrolyticcondenser containing a condenser body I2 having a pair of electrodeconnectors I4 and I6, and wrapped with an insulator I8. The electrodeconnectors I4 and I 6 are each secured in electrical relation to aterminal member 20 by means of an aluminum washer 22 against which theterminal 20 is riveted as at 24 after passing through an aperture in theelectrode connector I4 or I6, and through the washer 22.

The terminal members 20, and their mea-ns of support will be morespeciically described in paragraphs to follow. For enclosing thecondenser body I2 and for supporting the terminals 20 there is a casingcomprising two shallow pans or casing members 3l) and 32, each of whichhave iiat bottom walls and terminate in iiat rims or iins 3d and 36respectively. On one of the pans the flange, for instance the fin 34,has a peripheral ange 38 upstanding therefrom, and which is preferablynormal thereto, while the other pan, such as the pan 32 has its 1in 36of such width that the overall dimension of the pan will iit snuglywithin4 the fiange 38 of the cooperating flange.

One of the pans, for instance the pan 30, is provided with a pair ofdepressions 40, 42 near one end thereof, which amount to denting in thebottom wall of the pan toward the flange thereof, such as to provide arelatively flat portion 44 having an aperture 46. The bottoms of thedepressions 46 and 42 at the inner end of the ilat portion 44, and aboutthe aperture 46 are further depressed so as to form countersinks 48,that are concentric with the apertures 46. The countersinks 48 are thusjoined to the surrounding metal of the casing part 30 by thesubstantially upright walls 50, and the fiat portions 44 are joined onopposite sides by the abrupt rising portions 52 of the case member. Withthe casing member so fashioned the electrode terminals are thenceafflxed in the following manner.

The terminal members 2li extend from their flange or shoulder portionwith a stud portion 54 that is somewhat smaller in cross section thanthe diameter of the aperture 46 through the casing member. Over thisstud portion there is disposed a washer 56 of insulation, whose apertureis counterbored as at 58, the washer being so disposed on the stud thatthe recess provided by the counterbore 58 is on the side away from theshoulder 25. The terminal 20 with the insulator 56 thus in place, isinserted with its stud 54 extending from the inside of the casingthrough the aperture 46 of the housing member.

A washer 69 of mobile material, which may be soft rubber or likecompressible material, is passed over the end of the stud 54 and presseddown against the flattened portion 48 of the housing. So placing thewasher 6l) tends to centralize the stud 54 with respect to the opening46 since the washer 66 is nicely contained within the rising walls 50 ofthe countersink and the aperture of the washer closely embraces the stud54. Over the end of the stud 54 there is then placed a solder shield 62.'I'he solder shield 62 has an extension 64 on one side thereof, whoselateral sides 66 are straight walls and of a dimension to substantiallyll the space between the rising walls 52 of the casing depression. Theunderside of the solder shield is provided a countersink 68 about itsaperture 10, and outside of which there is an annular groove 12concentric therewith. The solder shield 62 is so disposed on the shank54 that the countersunk and groove portion is adjacent the mobile washer60. A plain metallic washer 'I6 is thence passed over the end of the lstud 54, which is followed by a solder lug 18 having a lead connectingtab 86.

While this assembly of elements upon the stud 54 are pressed together,the end of the stud 54 is peened over or riveted as at 82 which actioncauses the mobile washer 60 to be severely compressed an-d flow throughthe aperture 46 of the casing into the countersink 58 of the insulator56, which thereby insulates the stud 54 from the casing 30. The pressurewith which the elements are forced together also causes the mobilewasher 66 to flow into and fill recesses 68 and 'l2 of the solder shield62. At the same time, the material of the mobile washer 6U is compressedto more firmly engage the shank of the stud 54, and the peripheralportion of the washer 60 is caused to flow laterally therefrom, such asto ooze out from between the solder shield 62 and the seating portion 43of the pan, substantially as indicated at 84 and 86.

It is to be noted that each of the elements 56, 66. 62, 16 and 'I8comprising the assembly to be passed over the stud 54, each have anaperture therethrough designed to closely embrace the shank of the stud.When these elements are forced into compressive relation upon the mobilewasher 60, all possibility of electrolyte or vapor leaks through theaperture 46 of the casing member is eliminated, and the terminal member20, due to the centralizing relation effected by the insulators, washersand formed walls of the casing depression, is electrically isolated fromthe pan, so as to eliminate any short circuits from that source. Sincethe sides 66 of the solder lug closely engage the rising walls 52 of thedepressed portion of the casing, rotation of the terminal assembly isobviated, which prevents rupture of the electrode connectors I4 withinthe enclosure and also prevents movement of the terminal 20 intoengagement with the metal of the pan on which it is mounted. All of themetallic elements within the casing that might be exposed to theelectrolyte therein are composed of corrosion resisting material, thuseliminating the possibility of corrosion or ionic dissolution. Theterminal parts are to be of film forming material. Having the condenserelectrodes so connected with the terminals, the casing members 3U and32are thence nested together with their fins 34 and 36 in contactingrelation.V With the parts in this position the edges only of the casingmay be dip soldered for sealing the two casing members together. Thesolder joint so effected is indicated at in Fig. 3. The constructionthus affords a simple and efficient means of sealing the two casingmembers together, and is one that may be practiced by an unskilledoperator, since it is-only necessary to hold the two casing memberstogether, and dip their edges into the solder bath. The constructionlends itself readily to a method of automatic soldering wherein theassembled units may be properly supported by conveyors or the like, thatdip and roll the edges of the vcasing members in the solder bath. Thepoint at which the casing members are soldered together is so remotefrom the active elements of the condenser that overheating of thecondenser section within the can is obviated. overheating-of thecondenser sections adversely affects the condenser, and may beconductive to oozing of the electrolyte from the seams that are beingsoldered. Such conditions were experienced in the conventional type ofcondenser casing of the long stan-ding rectangular casing, fitted with aBakelite enclosure providing a solder flange. `As a means offorestalling any diflculty with respect to electrolyte ooze andsoldering, we may elect to provide a small aperture 92 through one ofthe casing members, substantially as indicated in Fig. 1, so that if theoperator is slow in completing the solder connections of the casing, orsuch that if the condenser assembly is maintained in too hot a conditionWhile the soldering is being effected, that-a relief is afforded for theescape of a small portion of the electrolyte or gas therefrom while thesoldering is being effected. While so doing it is found that electrolyteleaks between the fins 34 and 36, while the unit is being soldered, willbe eliminated. At the conclusion of the rim soldering of the casingmembers the small aperture 92 is closed with a drop of solder, such asto maintain the assembly in sealed condition.

Electrolytic condensers so constructed are adaptable for mounting andelectrically connecting in banks, as shown in Fig. 5, where-a rack isprovided that includes a plurality of rails 54 and 8S each having spacedparallel notches 98 adapted to receive the sealed edges 33 of thecondensers IU. The rails 94 and 9S are of nonoonducting material, andpreferably have a strip of insulating material within the grooves andfolded over the edge 38 of the condensers. The condensers lll may beelectrically connected in any number of ways, one of which is suggestedby the dashed lines of Fig. 5.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted, all coming within the scope of the claims whichfollow.

What is claimed is as follows:

l. In an electrolytic condenser, the combination comprising, a casingmember `naving a depression therein and apertured for reception of aterminal member, said depression providing an annular recess about theaperture therethrough, a shouldered telminal having a shank ofrelatively small cross section as compared with the casing aperture, aninsulating washer closely iitting the shank of said terminal member andhaving an annular recess surrounding the said shank when the washer ismounted thereon, said shank passing through the casing aperture, andsaid insulator recess facing the wall of said casing member, a softrubber washer disposed on the opposite side of said casing member andclosely surrounding the shank of said terminal, a solder shield disposedover the shank and having grooves concentric with the shank engaging thesoft rubber washer, and means including a part of the shank forcing thesolder shield toward the insulating washer and for compressing the softrubber washer, whereby it flows into the depressions of the insulator,the enlarged aperture of the housing member and the grooves of thesolder shield, thereby eifecting complete insulation of the terminalmember from the housing, and completes a seal against uid flow throughsaid housing member.

2. In an electrolytic condenser, a shouldered terminal stud, a housingmember providing an aperture therethrough substantially larger than thesection of the stud, a pair of insulators closely surrounding the studand disposed one on either side of the housing member, said insulatorsbeing recessed concentric with their apertures, said insulators beingdisposed on the stud so that the recessed portions each face the housingmember, a washer of mobile material disposed between one of theinsulators and the housing member and closely surrounding the shank ofsaid stud, a backing washer axed against the outer of the insulators,said stud being riveted against the backing washer to compress themobile material, causing it to flow into the recesses of the insulatorsand into the enlarged aperture of the housing member for insulating andsealing the terminal member from the casing.

3. An electrolytic condenser comprising in combination, a condenser bodyhaving tabs secured to terminal members, a pair of substantiallysymmetrical housing members for enclosing the condenser body, one ofsaid housing members having aperturcd depressions for support of thesaid terminals mounted in the depressions, insulating means positioningthe terminals centrally of the apertures and insulating the terminalsfrom the housing member, said insulating means having non-roundedextensions engaging the wall of the housing depressions for preventingturning of the terminals relative to the housing, whereby loosening ofthe terminals and rupturing of the tabs is prevented.

4. In an electrolytic condenser under an hermetic seal, a casingassembly comprising in combination, a pair of shallow drawn thin gaugesheet metal pan-like members, each member having a perimetric rimoccupying a common plane, and adapted to engage the rim of the othermember, one of the pan members being further deformed to provide aperimetric ledge for receiving and locating the other pan member, andsaid one pan member being provided at one end thereof with a pair ofsymmetrical depressions projecting toward the interior of the casingassembly, said depressions including spaced lineally extending shoulderportions adapted to abut terminal insulators, a pair of electrodeterminals, means for mounting both terminals in insulated relation eachin one of the depressions and with respect to each other, wherebyterminal members therein mounted will be prevented from rotating orloosening and means sealing the members one to the other, to preventpassage of fluid matter at their rim junctures, said pan rims providingradiating ns for cooling of said condenser.

5. In an electrolytic condenser under an hermetic seal, a casingassembly comprising in combinaticn, a pair of shallow drawn thin gaugesheet metal pan-like members, each member having a perimetric rimoccupying a common plane adapted to engage the rim of the other member,a pair of electrode terminals, means for mounting both terminals ininsulated relation on the case assembly and with respect to each other,and means for sealing the members one to the other to prevent passage offluid matter at their rim junctures, said pan rims providing radiatingns for cooling of said condenser, said means for mounting the terminalscomprising depressed formations of one of the pan members each having anaperture therethrough, terminal studs with appropriate insulatorsmounted in the apertures, and a mobile gasket being disposed against thematerial of the pan depression and engaged by an outside insulator, allof said insulators being recessed to provide channels for reception ofthe mobile material when compressed, said outside insulator havinglateral extension and engageable with the walls of said pan depressionwhereby rotation of the terminal assembly is prevented and said outsideinsulator providing a shield against solder bonding the terminal memberto the pan member.

ALEXANDER M. GEORGIEV. PAUL F. KOEHLY.

